Recovery of gases



G. A. M. HEIM 2,488,665

RECOVERY OF GASES Filed Sept. 30, 1946 Nov. 22', 1949 Patented Nov. 22, 1949 UNITED STATES PATENT Y(lFFICE adverses RECOVERY F GASES Gustav Anton Maria Heim, deceased, late of Velp,

Netherlands, by Clementine H. H. Heim-Hoedemakers, executrix,` Velp, Netherlands, assigner to American Enka Corporation, Enka, N. C., a

corporation of Delaware Application September 30, 1946, Serial No. 700,262 In Germany May 21, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires May 21, 1961 (Cl. 18e-54) 2 Claims.

against hydrogen sulphide contamination.

In the spinning of rayon yarn of the viscose type, a viscose spinning solution is extruded through a spinnerette into a sulphuric acid bath. The reaction of the viscose with the acid of the bath results in the generation of hydrogen sulphide along the thread path immediately adjacent its point of emergence from the spinnerette. If this gas is allowed to accumulate in the spinning rooms in any substantial concentration,

acute discomfort to the operating personnel results.

In View of the foregoing, it has been customary to maintain in spinning rooms a high degree of ventilation in order that the operating personnel -may be protected. While the conditioning of air in spinning rooms has been successful in preventing injuryand acute discomfort to operating personnel, it is apparent that the procedure is inherently very wasteful since to the cost of air conditioning, which is not inconsiderable when heat-ing and humidifying requirements are met, must be added the economic value of the hydrogen sulphide which is wasted to atmosphere. Furthermore, the wasting of large quantities of hydrogen sulphide to atmosphere renders a good deal of the surrounding area untenable for residential purposes.

It has now been found possible by the practice of the present invention to reduce substantially the air conditioning requirements of rayon plants, to recover a large proportion of the hydrogen sulphide generated incident to spinning, and to avoid imparting objectionable odors to the surrounding atmosphere.

It is further an object of this invention toV attain the foregoing advantages in a technically simple way without interference with the normal spinning apparatus and processes.

Other objects and advantages of this invention will be apparent upon consideration of the following detailed description of two embodiments thereof in conjunction with the annexed drawings wherein:

Figure 1 is a diagrammatic representation of hydrogen sulphide recovery apparatus con- 2 structed in accordance with the present invention and illustrated in association with a single spinning position; and

Figure 2 is a diagrammatic representation of a i modied type of apparatus for the recovery of v,hydrogen sulphide which is also shown in association with a single spinning position.

Referring now in greater detail to Figure 1, the numeral i9 designates a spinnerette through which a viscose solution is extruded to form a thread II, the spinnerette being disposed below the surface of a spinning bath I2 which may be of any known composition but which may be assumed to contain a large proportion of sulphuric acid. After emergence from the spinning bath the'thread II is led upwardly over a revolving roller I3 and then downwardly into the bath again and around a roller Ill from which it is led upwardly to and around a godet I5 to a point ly conventional.

of collection or after treatment, not shown.

The foregoing spinning arrangement is entire- It is proposed, however, in accordance with the present invention, to dis-pose a hood I6 having depending portions Il in position above the spinnerette I!! in a position envelopin-gV the thread path from and to the surface of the Spin bath and the roller I3. The hood I6 is open at the bottom which lies below the surface of the spin bath I2 and is provided with a gas outlet conduit I8 near its top. The hood I6 is held in position by suspension at its top from a cable I9 which passes around a roller 29,1the cable at its end. remote from the 4end attached to the hood being provided with a counterweight 2|.

It can now be seen that the hood I6, in the position shown in Figure 1 is disposed above the spinnerette and enveloping a portion of the thread path so that gases evolved incident to reaction between the viscose and the sulphuric acid of the spin bath will be collected in the hood. These gases may be withdrawn through conduit I8 and subjected to known chemical processes for the recovery of either sulphur or sulphuric acid as may be required. Since most of the gas produced incident to a spinning operation is evolved immediately after the extrusion of the viscose, it is apparent that the present invention affords a high degree of recovery of hydrogen sulphide with concomitant reduction in the air conditioning requirements of the spinning room as a whole. In view of the fact that the roller I3 is disposed near the top of the hood it, and since in threading up it is necessary for the operator to pass the thread over the top of this roller, the hood I6 is mllnted for vertical adjustment. This adjustment is effected by pulling on the weight 2| to cause the hood to rise to a level such that the bottom of its depending flanges lies above the roller I3. In this position threading up can be effected conveniently and, after threading up, the hood may be restored to the position shown in Figure 1.

While the apparatus disclosed in Figure 1 involves a single hood above a single spinning position, it is apparent that an elongate hood may be used in association with a plurality of aligned spinning positions. In this case, threading up can be effected in groups and the gas recovered will be that emanating from the group of spinning positions. It is contemplated that the roller I3 will be supported for rotation by means, not shown, extending upwardly from a position below the bottom of the hood as shown in Figure 1, the supporting means being adapted to be enveloped by the hood. However, it is possible to mount the hoods in a stationary manner as indicated in Figure 2. In this case the hood 22 is mounted in fixed position above a spinnerette 23 by means not shown. A roller 24 is disposed in vertical sliding movement in a bearing 26 at the top of the hood 22. By this arrangement it is possible to lower the roller 24, as shown in broken lines, to a level below the bottom of the hood 22 so that the apparatus may be threaded up to produce a thread path of the same type as that disclosed in Figure l. The gas collection is effected in the same manner from hood 22 as was described above in connection with hood I6. In the event hood 22 is made in elongate form to accomodate a plurality of spinning points, it is contemplated that the rods 25 be connected together so that they may be raised or lowered simultaneously;

It is apparent that the foregoing disclosure of two embodiments of this invention is merely illustrative and that various modications are contemplated within the scope of the appended claims.

What is claimed is:

1. In the manufacture of viscose yarn wherein a viscose solution is spun through a spinneret into a conventional acid spinbath and the fresh- 1y formed yarn is withdrawn from the bath and returned thereto, the steps that comprise establishing a closely confining zone for the gases evolved during the spinning operation, said gas confining zone being located exclusively around the yarn path above the bath during the spinning operation, by enveloping the yarn path only above that part of the bath where the yarn leaves the bath while leaving the remainder of the bath open, with a gas conning enclosure between a point below the level of the spinbath and a point slightly above the peak of yarn travel whereby the gases evolved in said zone are relatively concentrated, and continuously withdrawing the evolved gases from said zone as the viscose solution is extruded into the bath.

2. In the manufacture of viscose yarn wherein a viscose solution is spun through a spinneret into a conventional acid spinbath and the freshly formed yarn is withdrawn from the bath in a substantially vertical direction and is then passed downwardly into the said bath, the steps that comprise establishing during the spinning operation a closely confining zone for the gases evolved during the spinning operation, said gas confining zone being located exclusively around the yarn lpath above the bath, by enveloping the yarn path only above that part of the-bath where the yarn leaves the bath while leaving the remainder ofthe bath open, with a gas confining enclosure between a point below the level of the spinbath and the point where said yarn begins its downward movement whereby the gases evolved in said zone are relatively concentrated, and continuously withdrawing the evolved gases from said zone as the viscose solution is extruded into the bath.

CLEMENTINE H. H. HEIM-HOEDEMAKERS. Eecutri of the Estate of Gustav Anton M aria Heim, Deceased.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 394,559 De Chardonnet Dec. 18, 1888 2,241,304 Heywood et al. May 6, 1941 2,302,971 Moritz et al Nov. 24, 1942 2,348,415 Polak May 9, 1944 2,393,595 Dawson Jan. 29, 1946 2,413,102 Ebert et al Dec. 24, 1946 OTHER REFERENCES The Rayon Industry by Avram, published by Nostrand Co., Inc. (Copy in U. S. Patent Oice Library-Second Edition 1929.) 

